1. Field of the Invention
The present invention relates to a socket connector, and more particularly to a central processing unit (CPU) socket connector for electrically interconnecting a CPU package and a printed circuit board (PCB).
2. Description of the Prior Art
A typical socket connector is adapted to electrically interconnect a PCB and an integrated circuit (IC) package such as a CPU package. Referring to FIG. 8, the socket connector 6 includes a base 60 mounted on the PCB (not shown), a cover 61 carrying the CPU package (not shown) thereon and slidably mounted on the base 60, a plurality of terminals 63 received in the base 60, and an actuator mechanism 62 movably engaged between the base 60 and the cover 61. The base 60 comprises a terminal receiving section 600, and an actuator receiving section 601 extending from one end of the terminal receiving section 600. An array of terminal-passages 6000 is defined in the terminal receiving section 600, for receiving the terminals 63 therein. The actuator receiving section 601 is raised relative to the terminal receiving section 600. An actuator channel 6010 is defined in the actuator receiving section 601, for pivotably securing the actuator mechanism 62 therein. An arcuate positioning cavity 6012 is disposed in the middle of the actuator channel 6010, and a diameter of the arcuate positioning cavity 6012 is greater than that of the actuator channel 6010. A sidewall 6011 is defined at one end of the actuator channel 6010, for preventing the actuator mechanism 62 from moving sideways in the actuator channel 6010. An array of holes 610 is defined in the cover 61 corresponding to the terminal-passages 6000, for insertion of pins of the CPU package therethrough. The actuator mechanism 62 includes a shaft 620, and a handle lever 621 extending perpendicularly from one end of the shaft 620. Cam portions 6200 are formed in the shaft 620, the cam portions 6200 being pivotably received in the actuator channel 6010 of the base 60. A protrusion 6201 is formed in the middle of the cam portion 6200, corresponding to the arcuate positioning cavity 6012. The cover 61 is urged to an open state in which the terminal-passages 6000 are aligned with corresponding holes 610, so that the pins of the CPU package are inserted into the corresponding terminal-passages 6000 with zero insertion force. After that, the cover 61 is urged to a closed state in which the pins mechanically and electrically engage with the corresponding terminals 63. The above features can be found in “Development of ZIF BGA Socket” (CONNECTOR SPECIFIER, May 2000, pp.16˜18). Thus good alignment between the holes 610 and the corresponding terminal-passages 6000 is key to assuring insertion of the pins of the CPU package with zero insertion force and avoidance of damage to the pins and the socket connector 6.
In assembling a CPU package onto the connector 6, the handle lever 621 is operated to rotate the shaft 620, so that the cam portions 6200 of the shaft 620 urge the cover 61 into the open state. The protrusion 6201 engages in the arcuate positioning cavity 6012, and makes the handle lever 621 of the actuator mechanism 62 stop at a vertical position. Thus the terminal-passages 6000 are aligned with the corresponding holes 610 to assure insertion of the pins with zero insertion force.
However, the actuator channel 6010 is defined in the actuator receiving section 601, and the arcuate positioning cavity 6012 is disposed in the middle of the actuator channel 6010, with the diameter of the arcuate positioning cavity 6012 being greater than that of the actuator channel 6010. This configuration reduces a strength of the base 60. Therefore, when the socket connector 6 is assembly or used, the base 60 is easily distorted or damaged if it sustains an unduly large force. When this happens, the terminal-passages 6000 are not aligned with the corresponding holes 610. The pins of the CPU package cannot be inserted with zero insertion force, and may be damaged during insertion. Socket connectors having shortcomings similar to those described above in relation to the socket connector 6 can be found in Taiwan Pat. Issue Nos. 502882, 481378, 481375 and 481360.
Thus, there is a need to provide a new socket connector that overcomes the above-mentioned problems.